I just bought a Moog Midi Murf… my first Moog product, and I am blown away by the sound and build quality. I’m having an issue with it though. If I turn the pattern animation off… and turn the lowest filter band up and then use midi cc 3 to sweep the cutoff position… there’s a spot that I can hit where the filter self oscillates. If I turn the LFO on and let it control the cutoff sweep… every time the cutoff is swept past that self oscilation pointi it makes a clicky/thumping sound and repeats/slowly fades away. Anyone else have points on their murf filters where they self oscillate like that? I’m thinking I’ll have to send it back for a replacement.
Sounds like an issue with the lowest filter. We might need to replace a capacitor in there. This would be covered by your warranty if the unit is less than 12mos old… sorry for the trouble!
-Amos
Ok cool, yeah I just got it a couple of days ago through Sweetwater online. What’s the turnaround time on something like that? Trying to decide if I should just send it back to Sweetwater for a new one or send it in to you guys.
Probably a week or two depending on how busy they are.
I wanted to follow up on this… Sweetwater sent me a replacement midi murf and it has the same issue. I’m thinking maybe this is just how the lowest filter band functions when the Murf is in “Mids” mode. Here’s a wave file showing what it does. I’m just tapping one note… the same note in all of the examples within the wav file. There is no release to the patch/sound I’m using so as soon as I lift my finger off the key I would expect the murf to stop making noise.
The LFO is turned on, murf is set to pattern 1 (no animation), I have a knob on my midi controller set to send out midi cc3 messages… and I used that to speed up the LFO. The first two sounds are me pressing and quickly releasing the note with only the lowest filter band up. Then I turn the lowest band all the way down and do the same thing with only the 2nd filter band up, then only the 3rd filter band up etc… then back to only the lowest band. You can hear how with the lowest band, the lfo movement feeds back or or something and repeats where the other bands stop making noise immediately after you stop pressing the key.
Anyway, since this happens with both Murfs I’m assuming this is just how it functions. Can someone else confirm?
subtle bump… can anyone confirm their midi murf does this? I just want to make sure this is how they all function and Sweeterwater didn’t ship me TWO defective units:
Got to it and yes, same issue for me.
To be honest, I spend most, if not all of my time on the Bass freq range so had not noticed this, but I tested the following.
- Tested as you did using Midi CC#3 with a gate pedal on from my Phatty using CA (Calibration tone, preset “CA”); it’s best because there is no frequency offset from a 2nd OSC or LFO induced modulation.
200 Hz. filter produces a distinct beating or dull clicking time for each 2 1/2 cycles of the LFO. I wouldn’t say that it’s self oscillation though.
Sounds more like noise coming form the LFO that pulses throughout the note hold (though not as noticeable until you release the key). At that point there is a rather long release during which the pulsing fades much lower, eventually settling to a fairly low level (but you can hear it clearly if you boost up the volume, especially through headphones).
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Did the same with an EP-2 expression pedal, same result.
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Thinking it was perhaps noise from the internal LFO, I hooked an external LFO up using my Multipedal to drive CV to find that CV driving the same circuit produces the same result.
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Then I turned the LFO switch off to affect a Sweep instead of LFO, plugged my EP-2 back in and noticed something strange. That at the exact top of the range (toe position with attenuator turned up all the way), you can detect the step/pulsing, but without an LFO cycling and the decay, it just hits at a specific point on the pedal.
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Stepping over to Midi now, I tweaked a knob on my MPK25 to find that the clicking is actually a step in frequency (sounds like an overtone) that occurs precisely at CC#3 value=119. AT 118 or 120 (or anywhere else for that matter) you do not hear it depending on the note played.
I don’t have an O-scope, else I could pinpoint the frequency.
Note that if you listen closely, there is also an anomaly down between data value 0 and 1 but it’s barely noticeable.
So there are two issues and possibly a way to fix this, one is to ensure that the range of sweeping (whether done manually or via the LFO) does not cycle beyond this upper range which is at the top of the course midi setting (values range form 0..127). Not sure if there is a trim pot inside that Moog can tune.
I’m not quite sure why the release mentioned above is so slow on the lowest filter in Mid setting. Even if this could be tweaked/fixed, you’d still hear the pulsing, except it would be drowned out by the audio.
Would be interested in reading a response from Moog on this. Am sure they can isolate it to an exact frequency and provide an explanation as to why it is happening.
I am having this same problem, except Im not using MIDI with mine, haven’t even gotten that far yet. Im notiging a distinct hum as well (the note B) on the same thing. I thought it sounded like a power supply surge because of the pulse that occured immediately before the hum but I don’t know much about electronics, but I have heard similar noises when something else was plugged in or turned on.
I emailed Ryan, hopefully Ill hear something by Monday morning, Im going to send it back if he says this is something that requires it. Mine has a hum that I thought at first was related to the resonant frequency, but its pretty overbearing when Im playing quiet things that leads me to believe it is something else.
Anyway, Im glad I caught this now instead of down the line.
Eric
Please keep us posted, I’m looking to “upgrade” to one of these very shortly. 
Cheers
Andy
Sent mine back today, well see what happens
Did you talk to them on the phone about it? I was kind of waiting to see what they’d say on the forum. I already had Sweetwater send me a replacement and it has the same defect so I was assuming it is part of the design and that they all have this problem. Maybe I’ll send it in to Moog too and see if they can fix it.
Ryan asked me if it is making this type of noise with nothing pluged into it.
There was a definite hum of the lowest filter in the Mids section. If I hooked it up to my mixer and used headphones, with the gain and faders and volumes high, as the filter would sweep the lights would flash registering a signal coming in when none was going into the murf.
At regular volume levels, almost as if the Murf had a vca, if I plucked a string on my bass and muted the string, there was a hiss, followed by a pop and a hum like it was the note B that was audible until what resembled a VCA would mute itself.
He said that the unit shouhldn’t be any noiser than any other Fooger and that if the filters were making noise by themselves then theres a problem that needs repairing.
I can’t wait to get it back and to get my MIDI interface so I can start programming rhythms.
Just go ahead and submit your RMA request so you can hury and get yours back.
Eric
Did Moog end up fixing this for you?
Ive been in contact with Ryan, Im expecting it soon but I don’t really know the status of the repair yet. He did say that he would be making some improvements, but thats the last I heard from him. I keep checking the porch and watching for the ups truck because it could very well be
I was noticing the problem when I was playing my bass..with active pickups. I would hit the string and immediately mute it, and if I listened I coudl hear something like the effect was still engaged but it was silent. WHen it reached that filter, I would hear the click and thump described in the original post, but I could also hear a hum that was he note B which resembled line noise. I tested it in diferent areas, hooked it to the mixer, maxed out all the gains and I could hear it. It took me a few days to really notice it.
Hi all,
I think I have just put the last finishing touches on the Midi MuRF firmware update. It definitely fixes this “thump” problem.
We should have a firmware update utility for Windows PC within the next week, and then I can release this update into the wild.
We are not 100% sure about a Mac-based update utility, but if it’s technically feasible we will make a Mac version also. (there might be a compatibility issue with Core Midi; we’re looking into it).
Cheers,
Amos
Say it isn’t so… does MuRF not respond to SysEx? I only have Mac’s at this point and recall flashing the code in my MuRF after first getting it (I may have made that part up!)
Please do what you can to support us poor Mac folk. EricK will be most upset as he just ‘converted’ to Mac albeit reluctantly! : )
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Some big thanks also to UCAudio, EricK, and EMwhite for pointing out the thump issue in such useful detail!
An admirable example of how to help a company to help you with an issue.
Amos,
Im sure you still have my MURF there, please don’t feel rushed. TELL RYAN to take all the time he needs. Tell him that im in no hurry, especially if its a firmware issue.
EM,
I still have a pc here I can use, though it is crappy. There was no reluctance whatsoever about me moving to mac, except the cost.
Thanks again, Amos.
I got my Murf Today and it sounds really great. My problems are eliminated, and FWIW, I got my Taurus Shirt in there too.
Thanks guys for your work.
Eric
I’m having the same problem, not using midi though. I’m hearing clicks when I’m not playing at all when the envelope is either set between 0 and 2 or 8 and 10. Is this normal? Also seems to be a lot of white noise in general.